Dipole Effects on Electron Transfer are Enormous
Dipole Effects on Electron Transfer are Enormous
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DOI：
10.1002/anie.201802637
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发表时间：
2018-09-17
影响因子：
16.6
通讯作者：
Vullev, Valentine I.
中科院分区：
文献类型：
--
作者：
Krzeszewski, Maciej;Espinoza, Eli M.;Vullev, Valentine I.
分子偶极子是指导电子转移（ET）过程的重要方法，但尚未得到充分利用。虽然偶极子在其附近产生每米千伏的电场，但报道的沿偶极子和反偶极子的ET率之间的差异通常很小或无法检测到。在这里，我们展示了前所未有的大偶极子效应对ET的影响。根据它们的取向，偶极子要么确保皮秒ET，要么完全关闭ET。此外，有利的偶极子取向使得即使在亲脂介质中也可以实现ET，这对于不带电的供体-受体系统来说似乎是违反直觉的。我们的分析表明，偶极子可以大大改变低溶剂极性的ET驱动力，这解释了这些独特的趋势。这一发现为引导ET过程向前发展，同时抑制不希望的反向电子转导打开了大门，这是光物理学和能量科学的圣杯之一。
Molecular dipoles present important, but underutilized, methods for guiding electron transfer (ET) processes. While dipoles generate fields of Gigavolts per meter in their vicinity, reported differences between rates of ET along versus against dipoles are often small or undetectable. Herein we show unprecedentedly large dipole effects on ET. Depending on their orientation, dipoles either ensure picosecond ET, or turn ET completely off. Furthermore, favorable dipole orientation makes ET possible even in lipophilic medium, which appears counterintuitive for non-charged donor-acceptor systems. Our analysis reveals that dipoles can substantially alter the ET driving force for low solvent polarity, which accounts for these unique trends. This discovery opens doors for guiding forward ET processes while suppressing undesired backward electron transduction, which is one of the holy grails of photophysics and energy science.